Cyclical deposition of a variable content titanium silicon nitride layer

Abstract

Embodiments of the invention relate to an apparatus and method of depositing a titanium silicon nitride layer by cyclical deposition. In one aspect, a titanium silicon nitride layer having a variable content or a controlled composition of titanium, silicon, and nitrogen through the depth of the layer may be formed. One embodiment of this variable content titanium silicon nitride layer or tuned titanium silicon nitride layer includes a bottom sub-layer of TiSi X1 N Y1 , a middle sub-layer of TiSi X2 N Y2 , and a top sub-layer of TiSi X3 N Y3 in which X1 is less than X2 and X3 is less than X2. Another embodiment of a variable content titanium silicon nitride layer includes a bottom sub-layer of TiSi X1 N Y1 and a top sub-layer of TiSi X2 N Y2 in which X2 is greater than X1. Still another embodiment of a variable content titanium silicon nitride layer includes a bottom sub-layer of TiSi X1 N Y1 , a middle sub-layer of TiSi X2 N Y2 , and a top sub-layer of TiSi X3 N Y3 in which X1 is greater than X2 and X3 is greater than X2.

What is claimed is:  
     
       1. A method of forming a variable content titanium silicon nitride layer, comprising: 
       (a) providing pulses of a titanium precursor;  
       (b) providing pulses of a silicon precursor and providing pulses of a nitrogen precursor at a ratio of the silicon precursor to the nitrogen precursor; and  
       (c) decreasing the ratio of the silicon precursor to the nitrogen precursor.  
     
     
       2. The method of  claim 1 , wherein providing pulses of a titanium precursor comprises dosing pulses of the titanium precursor into a purge gas stream and wherein providing pulses of a silicon precursor and providing pulses of a nitrogen precursor comprises dosing pulses of the silicon precursor and dosing pulses of the nitrogen precursor into a purge gas stream. 
     
     
       3. The method of  claim 1 , further comprising providing pulses of a purge gas between the pulses of the titanium precursor and pulses of the silicon precursor and the nitrogen precursor. 
     
     
       4. The method of  claim 1 , wherein the pulses of the silicon precursor and the nitrogen precursor at least partially overlap. 
     
     
       5. The method of  claim 1 , wherein the pulses of the silicon precursor and the nitrogen precursor are delivered separately. 
     
     
       6. The method of  claim 1 , wherein the variable content titanium silicon nitride layer is formed over a titanium layer. 
     
     
       7. The method of  claim 6 , wherein at least a portion of the titanium layer is converted to titanium suicide. 
     
     
       8. The method of  claim 6 , wherein the titanium layer is deposited over a metal silicide layer. 
     
     
       9. A method of processing a substrate, comprising: 
       forming a variable content titanium silicon nitride layer, comprising:  
       delivering a silicon precursor, a titanium precursor, and a nitrogen precursor to the substrate at a first ratio of silicon precursor to nitrogen precursor, and  
       delivering the silicon precursor, the titanium precursor, and the nitrogen precursor to the substrate at a second ratio of silicon precursor to nitrogen precursor, and  
       delivering the silicon precursor, the titanium precursor, and the nitrogen precursor to the substrate at a third ratio of silicon precursor to nitrogen precursor; and  
       forming a copper material layer over the variable content titanium silicon nitride layer.  
     
     
       10. The method of  claim 9 , wherein the first ratio is less than the second ratio and wherein the third ratio is less than the second ratio. 
     
     
       11. The method of  claim 10 , wherein the variable content titanium silicon nitride layer is formed over a dielectric layer. 
     
     
       12. The method of  claim 11 , wherein the dielectric layer comprises a low-k dielectric layer. 
     
     
       13. The method of  claim 12 , wherein the dielectric layer comprises a low-k material selected from the group including oxidized organosilane film and oxidized organosiloxane film. 
     
     
       14. A method of forming a variable content titanium silicon nitride layer, comprising: 
       (a) providing pulses of a titanium precursor;  
       (b) providing pulses of a silicon precursor and providing pulses of a nitrogen precursor at a ratio of the silicon precursor to the nitrogen precursor;  
       (c) increasing the ratio of the silicon precursor to the nitrogen precursor; and  
       (d) decreasing the ratio of the silicon precursor to the nitrogen precursor.  
     
     
       15. The method of  claim 14 , wherein the variable content titanium silicon nitride layer is formed over a dielectric layer and a conductive material layer comprising copper. 
     
     
       16. The method of  claim 14 , wherein providing pulses of a titanium precursor comprises dosing pulses of the titanium precursor into a purge gas stream and wherein providing pulses of a silicon precursor and providing pulses of a nitrogen precursor comprises dosing pulses of the silicon precursor and dosing pulses of the nitrogen precursor into a purge gas stream. 
     
     
       17. The method of  claim 14 , further comprising providing pulses of a purge gas between the pulses of the titanium precursor and pulses of the silicon precursor and the nitrogen precursor. 
     
     
       18. The method of  claim 14 , wherein the pulses of the silicon precursor and the nitrogen precursor at least partially overlap. 
     
     
       19. The method of  claim 14 , wherein the pulses of the silicon precursor and the nitrogen precursor are delivered separately. 
     
     
       20. The method of  claim 14 , wherein the variable content titanium silicon nitride layer is formed over a conductive material layer comprising copper. 
     
     
       21. The method of  claim 14 , wherein the variable content titanium silicon nitride layer is formed over a dielectric layer. 
     
     
       22. The method of  claim 21 , wherein the dielectric layer comprises a low-k dielectric layer. 
     
     
       23. The method of  claim 22 , wherein the dielectric layer comprises a low-k material selected from the group including oxidized organosilane film and oxidized organosiloxane film. 
     
     
       24. A method of forming a variable content titanium silicon nitride layer, comprising: 
       (a) providing pulses of a titanium precursor;  
       (b) providing pulses of a silicon precursor and providing pulses of a nitrogen precursor at a ratio of the silicon precursor to the nitrogen precursor;  
       (c) decreasing the ratio of the silicon precursor to the nitrogen precursor; and  
       (d) increasing the ratio of the silicon precursor to the nitrogen precursor.  
     
     
       25. The method of  claim 24 , wherein providing pulses of a titanium precursor comprises dosing pulses of the titanium precursor into a purge gas stream and wherein providing pulses of a silicon precursor and providing pulses of a nitrogen precursor comprises dosing pulses of the silicon precursor and dosing pulses of the nitrogen precursor into a purge gas stream. 
     
     
       26. The method of  claim 24 , further comprising providing pulses of a purge gas between the pulses of the titanium precursor and pulses of the silicon precursor and the nitrogen precursor. 
     
     
       27. The method of  claim 24 , wherein the pulses of the silicon precursor and the nitrogen precursor at least partially overlap. 
     
     
       28. The method of  claim 24 , wherein the pulses of the silicon precursor and the nitrogen precursor are delivered separately. 
     
     
       29. The method of  claim 24 , wherein the variable content titanium silicon nitride layer is formed over a titanium layer. 
     
     
       30. The method of  claim 29 , wherein a portion of the titanium layer is converted to a titanium suicide. 
     
     
       31. The method of  claim 29 , wherein the titanium layer is deposited over a metal silicide layer. 
     
     
       32. A method of processing a substrate, comprising: 
       forming a variable content titanium silicon nitride layer, comprising:  
       delivering a silicon precursor, a titanium precursor, and a nitrogen precursor to the substrate at a first ratio of silicon precursor to nitrogen precursor, and  
       delivering the silicon precursor, the titanium precursor, and the nitrogen precursor to the substrate at a second ratio of silicon precursor to nitrogen precursor; and  
       forming a copper material layer over the variable content titanium silicon nitride layer.  
     
     
       33. The method of  claim 32 , wherein the variable content titanium silicon nitride layer is formed over a dielectric layer. 
     
     
       34. The method of  claim 33 , wherein the dielectric layer comprises a low-k dielectric layer. 
     
     
       35. The method of  claim 34 , wherein the dielectric layer comprises a low-k material selected from the group including oxidized organosilane film and oxidized organosiloxane film.